PARIS - Europe's Venus Express satellite, which entered Venus orbit in April, has cleared its commissioning phase and is ready to begin formal operations despite the fact that one of its seven observing instruments is not functioning, the European Space Agency (ESA) said July 12.

The Planetary Fourier Spectrometer (PFS), which encountered problems in May, is stuck in "closed" position despite weeks of efforts to return the instrument to operations, ESA said.

"[A] series of activities and further in-orbit tests [will] be conducted in the next months, as well as a series of independent investigations, to examine the origin of the problem," ESA said in a July 12 statement on Venus Express' status. "In the meantime, other instruments will cover some of the PFS objectives."

The PFS is designed to measure Venus' surface and atmospheric temperature. Part of its mission is to hunt for volcanic activity on the planet.

Venus Express was launched in November 2005 and entered Venus orbit in April, after which it began adjusting its position to arrive at the highly elliptical orbit in which it will operate. The satellite will view Venus from distances of between 66,000 kilometers and 250 kilometers.

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